'65 skylark v8-300 The engine is mixing water with oil. I've been told it's the head gaskets. is that true? please help What do i need to do to fix that? please advice Marvin los angeles
The pros will chime in a clean-up/correct my response as necessary. If you have water in your oil it can be a blown headgasket, cracked cyllinder bore/head or loose cyllinder head bolts. You can check your plugs to see which ones are fouled and that will tell you the suspect cyllinders. You need to buy a headgasket kit which has all the gaskets necessary for repairing the leak. Intake has to come off Valve covers have to come off cyllinder heads have to come off Heads should be checked and cleaned up by a reputable machine shop. Now would be the time to do roller rockers, port and polish heads and/or intake and get dressier valve covers if you don't like the ones you have. Don't take the above like it is etched in granite; as you will read as more knowledgeable folk respond.
ya, most likely a head gasket. If you do find out which side is leaking, replace both anyway. The new gaskets are thicker and will lower your compression slightly. There are original stlye gaskets available that are the thin type, but are more expensive. I don't know if they have it for the 300. like jim said you should have the head cleaned up a a shop, take a few thousands off. The new gaskets are usually .023" thicker than the original types. Measure what you take out of there to be sure. You can have this much taken of the head and it will keep your current compression. I'd have a valve job done while you're in there 38 year old valve seat could probally use a cleaning up....
One other thing... sometime a car will get a little bit of water mixing with the oil and it is not the head gasket. It usually appears in a form of foam on the top of the valve covers. I had this on a car a while ago. I was told that it was my beat piston rings. Water is a byproduct of the combustion and if you have enough blowby past the rings, this moisture will end up in the crank case.... You can pressure test you coolant system, make sure that the water in the oil is coming from the cooling system.
300 head gaskets I have replaced a few 300 head gaskets over the years and I have found the only ones that work for me are the plain steel ones. Postons sells these alone or with a full kit. Install them as orginal with engine oil only. Machining the surfaces helps but I have had good luck with a cleaning as well. Alex Kiresuk
One last thing to consider. You could have a leak in the intake manifold gasket. You will get coolent in the oil that way also. To check for this do a compression check. One or two cyl. may be way above the rest. Also if you pull spark plugs and find one or two that are really clean compared to the others than that is where the problem lies.
I may be chiming in too late but, if it helps than great. I have the same motor and recently had the same issue. Do not be surprised how far you can go with a blown head gasket and not know. These 300's are tough little suckers. If you are thinking of taking this job on yourself than there are a few things to consider before turning the first bolt. I'll get to that in a sec. The common issue with these is that if the motor was "rebuilt" 1. they dont all use a spray sealant on the headgaskets. You should if you want reliability and are not concerned with the billionth of a pound compression loss by thickening the gasket slightly. Use Permatex copper spray. Lightly coated the gasket will seal and NEVER blow again unless you do something totally stupid. It's sticky and has copper in it. Helps keep the gasket in place when installing and deals with any impurities on the block very well. Also because of the actual copper in the spray, creates a good thermal bond. Alot of guys dont use anything and thats ok too if you're under that hood alot and have the heads and block surfaces flat and pure. If you've never done this before, use the spray, you wont be sorry. I've seen where someone had another sealer and screwed it up by not getting it even and thats one of the reasons for not using any but, the spray is real easy to do correctly. 2. I have found that loose head bolts cause this problem. When they send you home in your "rebuilt" engine, they never tell you "hey, bring it back in one month so we can re-torque the heads for you" When I dealt with mine I was amazed that my head bolts were coming out BY HAND! Fortunately in my case there was no damage beyond just the gasket. Try taking off the valve covers and with a small wrench (not a torque wrench) test to see if you turn any of the bolts easily. You may be amazed as I was. While you're at it, the same can apply to the intake manifold. Ok, things to consider before starting this. What is your goal for this motor? Speed? Stock? or just simply get her back on the road and running nicely. What are your long term plans for the car? Do you have the time and funds available to reach your goal? What worms will you open when you go in? Will you want to paint and restore parts as you remove them? You may get the bug as you get into it and start wanting it all!....I did, I'm not regreting a thing but, it did take a hell of alot longer than my original plan. Preparation. Tools, location, parts. Gasket kit which should come with all you'll need. You will need a variety of cleaning and scraping tools. Atleast three types of gasket sealer: The copper for heads and exhaust. That aviation stuff, i forget the name, its a permatex product, I can go look if you need, works great for intake. And some regular blue/black. A Torque wrench. Several trays for bolts and parts etc. Basicly what I'm getting at is, it's very do-able, just have a plan, be prepared and get help from guys in here. Parts, advice, tech help and personal experience is only a clik away. Dont be in a rush! It's too depressing when you do all this and screw it up. Good luck, and feel free to ask more questions before going in. Nick
